It is already known to weave in one and the same weaving machine felts having, for example, different widths. In weaving of this type use is made of a weaving machine which is fully rigged with warp and has a weave width which corresponds to the maximum weave width of the felt which is to be produced. The warp thread magazine can in this case incorporate so-called flanged bobbins on which the warp threads are wound. Each bobbin can have a width of approximately 250 mm. In previously known equipment it has been proposed to thread up the flanged bobbins on a common warp beam which is provided with a longitudinal wedge for bringing together all the bobbins.
As an example of the application of the woven product, mention may be made of a paper machine in which the paper web is conveyed through the machine on different types of woven wires and felts which serve as conveying belts for the paper during the manufacturing process. The felts or the like can in this case be divided into two groups, namely, on the one hand, flat woven felts and, on the other hand, round-woven felts. The flat-woven felts run in the paper machine in the warp thread direction and, when weaving such a felt, the weave width is set such that it corresponds to the roller width of the paper machine. The weave length corresponds to the circumference of the roller group in which the felt is to run. In order to produce a continuous conveying belt from a flat-woven felt, some type of coupling arrangement is used.
The round-woven felts run in the paper machine in the weft thread direction and, when weaving such a felt, the weave width is set such that it corresponds to half the circumference of the roller group in which the felt is to run. The weave length corresponds to the roller width of the paper machine. This type of felt is thus woven as a continuous conveying belt and no coupling arrangement is necessary in this case.
The paper machines which are used in various parts of the world have individual designs and operate with different functions. The requirement for offering felts and wires having different widths is thus considerable. In this connection it may be mentioned, among other things, that it should be possible for a number of felts of varying weave width to be produced using the same warp load.
When weaving the types of products in question here, it is necessary to produce in one and the same weaving machine felts and wires having different widths, with the machine being easily adjustable for changing the widths as the delivery sequence demands. In weaving machines proposed to date, it has been suggested that the surplus warp which is not being incorporated in the width of the current felt should be guided alongside the weaving process and removed as waste. This due to the fact that all the bobbins on the warp beam are coordinated from the point of view of rotation and that the unrolling takes place from all the bobbins regardless of the number which are involved in the on-going weaving process or are uncoupled from the weaving process. It has therefore been proposed to set up the warp thread width in accordance with the maximum desired width of the felt which could possibly be woven in the machine. When reductions in the weave width are made in relation to the maximum width, the warp thread waste arises. The reduction in the weave width can, in the types of weaving machines in question here, amount to a total of 50%, that is 25% per machine side. This means that for some felts 50% of the total warp is lost as waste. This waste represents a heavy cost to be borne by felt weavers and the users of the weaving machines, and there is a requirement to make it technically possible to eliminate at least the major part of this wastage. The purpose of the present invention is to solve, among other things, these problems.
The principles used hitherto for warp thread magazines and feeding of warp thread into weaving machines have meant, among other things, that all co-rotating bobbins must be wound with the same winding force and have the same diameter for the warp threads. It is desirable that this need for mutual correspondence be eliminated or substantially reduced. The present invention solves this problem too.
In previously used weaving machines, the bobbin stand has been very complicated from the mechanical point of view, using a common warp beam which has required large driving gear boxes, interior support bearings, and the like. It is desirable that this mechanical structure be considerably simplified. The invention aims to solve also this problem.
There is also a need to simplify the feeding-in functions in weaving machines. Thus, for example, it should be possible for the feeding-in function to be independent of the pertaining diameters of the bobbins and operate, for example, with a conventional stepping motor drive. The present invention also provides a solution to this problem.
The weaving machines represent a substantial capital investment and it may, therefore, be advantageous to complement existing weaving machines with the present invention. There is therefore a requirement for it to be possible to complement weaving machines of standard configuration and known designs with the equipment according to the present invention. This problem is also solved by the present invention.